On those cars equipped with the 'salt-shaker' glow indicator, there is also the large knob used to provide the glow, start, run, and fuel cut-off functions handled by the key on later models. This knob is known as the 'gorilla' knob. The 'salt-shaker' glows along with the real glow plugs in each pre-chamber, and I believe is in series with the rest of them. The timing relay is located inside the head of the vehicle operator.

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1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150